/**
 * Created with IntelliJ IDEA.
 * Description:
 * User: 666
 * Date: 2022-10-28
 * Time: 12:33
 */
//斐波那契数
public class Q {
    public static void main(String[] args) {
T t=new T();
int ret=t.fibonacci(4);
        System.out.println(ret);
    }
}
class T{
    public int fibonacci(int n){
        if(n==1 || n==2){
            return 1;
        }else{
            return fibonacci(n-1)+fibonacci(n-2);
        }
    }
}